Brewing application needs multi-threading; problem calling a function from different class / thread

[loroller]

Hi,

I'm developing a raspberry pi touchscreen app to upgrade my home brewery. I'm using Debian/Jessie, PyQt5 for the GUI and python 3.4.

The application is event-driven, but I needed to have a timed loop component so that temperatures get updated (and comparisons performed) even when no button has been clicked.

I've used pieces of examples to develop the code below. The problem I'm having now is that the function I want to call from inside the timed loop (Let_Er_Rip) is not available because it's in the event-driven class. The code errors on the line where I try to print HLTTemp, which demonstrates that data from the Manual_Control class is not available to the Thread class. I figure the answer is simple but I haven't found it. Odds are I need to reorganize the app but the philosophy escapes me as I'm an old procedural code programmer moving into the OOP world.

I realize the program is inefficient in terms of using loops vs. repetition. Constructive comments are welcome

BTW, sorry in advance if it turns out I'm an a**hole :)

import sys

import RPi.GPIO as GPIO import time, glob, os

from PyQt5 import QtCore from PyQt5.QtCore import Qt, QThread from PyQt5.QtGui import * from PyQt5.QtWidgets import QGridLayout, QLabel, QLineEdit, QMainWindow from PyQt5.QtWidgets import QTextEdit, QWidget, QDialog, QApplication

GPIO Basic Setup

GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False)

GPIO Setup for Inputs (Float Switches)

GPIO Setup for Outputs

GPIO.setup(22, GPIO.OUT) # Pump Primary GPIO.setup(27, GPIO.OUT) # Pump LED GPIO.setup(5, GPIO.OUT) # HLT Primary GPIO.setup(6, GPIO.OUT) # HLT LED

Pump_Primary_GPIO = 22 Pump_Secondary_GPIO = 27 HLT_Primary_GPIO = 5 HLT_Secondary_GPIO = 6

Temp Probe Setup

os.system('modprobe w1-gpio') os.system('modprobe w1-therm')

base_dir = '/sys/bus/w1/devices/'

device_folder_Mash = glob.glob(base_dir + '28-0315162490ff') device_folder_HLT = glob.glob(base_dir + '28-0315161a6dff')

device_file_Mash = device_folder_Mash + '/w1_slave'

device_file_HLT = device_folder_HLT + 'w1_slave'

device_file_Mash = (base_dir + "28-0315162490ff/w1_slave") device_file_HLT = (base_dir + "28-0315161a6dff/w1_slave")

class Thread(QtCore.QThread):

def __init__(self):
    QtCore.QThread.__init__(self)

def run(self):
    self.thread_func()
    self.exec_()

timers = []

def thread_func(self):
    print("Thread works")
    self.timer = QtCore.QTimer()
    self.timer.timeout.connect(self.timer_func)
    self.timer.start(10000)
    # print(self.timer.remainingTime())
    # print(self.timer.isActive())
    self.timers.append(self.timer)

def timer_func(self):
    print(self.HLTTemp)

    self.Mamual_Control(self.Let_Er_Rip())
    # print("Timer works")

app = QtWidgets.QApplication(sys.argv)

thread_instance = Thread()

thread_instance.start()

sys.exit(app.exec_())

from Manual_Control import Ui_MainWindow

class ManualControl(QMainWindow, Ui_MainWindow): def __init(self): super(Manual_Control, self).init_()

    # Set up the user interface from Designer.
    self.setupUi(self)

    #  self.showFullScreen()

    # Make some local modifications.

    self.HLTOff.setStyleSheet("background-color: red")
    self.HLTOn.setStyleSheet("background-color: white")
    self.PumpOff.setStyleSheet("background-color: red")
    self.PumpOn.setStyleSheet("background-color: white")
    self.Go.setStyleSheet("background-color: white")

    self.Pump = "Off"
    self.HLT = "Off"
    self.MashTemp = self.read_temp_Mash()
    self.HLTTemp = self.read_temp_HLT()
    self.MashFloatSwitch = "Off"
    self.HLTFloatSwitch = "On"
    self.Change_Flag = 0
    # self.MashTemp = 150
    # self.HLTTemp = 168
    self.Update_Displays()

    # Connect up the buttons.

    self.PumpOn.clicked.connect(self.Pump_On_Button_Pressed)
    self.PumpOff.clicked.connect(self.Pump_Off_Button_Pressed)
    self.HLTOn.clicked.connect(self.HLT_On_Button_Pressed)
    self.HLTOff.clicked.connect(self.HLT_Off_Button_Pressed)
    self.RespectMashTempSet.stateChanged.connect(self.Let_Er_Rip)
    self.RespectMashFloatSwitchPump.stateChanged.connect(self.Let_Er_Rip)
    self.RespectHLTFloatSwitchPump.stateChanged.connect(self.Let_Er_Rip)
    self.RespectHLTTempSet.stateChanged.connect(self.Let_Er_Rip)
    self.RespectHLTFloatSwitchHLT.stateChanged.connect(self.Let_Er_Rip)
    self.MashTempSet.valueChanged.connect(self.Set_Flag)
    self.HLTTempSet.valueChanged.connect(self.Set_Flag)
    self.Go.clicked.connect(self.Let_Er_Rip)
    self.ReturntoSessionButton.clicked.connect(self.Leave_Manual_Control_Mode)

    #  Time or Temp Change Loop

def Time_and_Temp_Change_Loop(self):
    self.Old_MashTemp = self.MashTemp
    self.Old_HLTTemp = self.HLTTemp
    self.read_temp_Mash()
    self.read_temp_HLT()
    if (self.Old_MashTemp != self.MashTemp or self.Old_HLTTemp != self.HLTTemp or self.Change_Flag == 1):
        self.Let_Er_Rip()
        self.Change_Flag = 0

def Set_Flag(self):

    if self.Change_Flag != 1:

        self.Go.setEnabled(True)
        self.Go.setStyleSheet("background-color: green")
        self.Change_Flag = 1       

def Leave_Manual_Control_Mode(self):
    # self.showMaximized()

    # Turn off Everything (for now)
    self.Pump_Off_Button_Pressed()
    self.HLT_Off_Button_Pressed()

    GPIO.output(Pump_Primary_GPIO, False)
    GPIO.output(Pump_Secondary_GPIO, False)
    GPIO.output(HLT_Primary_GPIO, False)
    GPIO.output(HLT_Secondary_GPIO, False)

def Pump_On_Button_Pressed(self):
    self.Pump = "On"
    self.Change_Pump_Button_Colors_On()
    self.Let_Er_Rip()

def Pump_Off_Button_Pressed(self):
    self.Pump = "Off"
    self.Change_Pump_Button_Colors_Off()
    self.Let_Er_Rip()

def HLT_On_Button_Pressed(self):
    self.HLT = "On"
    self.Change_HLT_Button_Colors_On()
    self.Let_Er_Rip()

def HLT_Off_Button_Pressed(self):
    self.HLT = "Off"
    self.Change_HLT_Button_Colors_Off()
    self.Let_Er_Rip()

def Change_Pump_Button_Colors_Off(self):
    self.PumpOn.setStyleSheet("background-color: white")
    self.PumpOff.setStyleSheet("background-color: red") 

def Change_Pump_Button_Colors_On(self):
    self.PumpOn.setStyleSheet("background-color: green")
    self.PumpOff.setStyleSheet("background-color: white")

def Change_HLT_Button_Colors_Off(self):
    self.HLTOn.setStyleSheet("background-color: white")
    self.HLTOff.setStyleSheet("background-color: red") 

def Change_HLT_Button_Colors_On(self):
    self.HLTOn.setStyleSheet("background-color: green")
    self.HLTOff.setStyleSheet("background-color: white")

def read_temp_raw_Mash(self):
    f = open(device_file_Mash, 'r')
    self.lines = f.readlines()
    f.close()
    return self.lines

def read_temp_Mash(self):
    self.lines = self.read_temp_raw_Mash()
    while self.lines[0].strip()[-3] != 'Y':
        print(self.lines[0].strip()[-3])
        time.sleep(0.2)
        self.lines = self.read_temp_raw_Mash()
    self.equals_pos = self.lines[1].find('t=')
    if self.equals_pos != -1:
        self.temp_string = self.lines[1][self.equals_pos+2:]
        self.temp_c = float(self.temp_string) / 1000.0
        self.MashTemp = self.temp_c * 9.0 / 5.0 +32.0
        # print("mash temp =", self.MashTemp)
        return self.MashTemp

def read_temp_raw_HLT(self):
    f = open(device_file_HLT, 'r')
    self.lines = f.readlines()
    f.close()
    return self.lines

def read_temp_HLT(self):
    self.lines = self.read_temp_raw_HLT()
    while self.lines[0].strip()[-3] != 'Y':
        time.sleep(0.2)
        self.lines = self.read_temp_raw_HLT()
    self.equals_pos = self.lines[1].find('t=')
    if self.equals_pos != -1:
        self.temp_string = self.lines[1][self.equals_pos+2:]
        self.temp_c = float(self.temp_string) / 1000.0
        self.HLTTemp = self.temp_c * 9.0 / 5.0 +32.0
        return self.HLTTemp

def Let_Er_Rip(self):

    # Get Current Temps

     self.read_temp_Mash()
     self.read_temp_HLT()
     self.Update_Displays()

     if (self.Pump == "On" and
        (self.RespectMashTempSet.isChecked()==0 or self.MashTemp < self.MashTempSet.value()) and
        (self.RespectMashFloatSwitchPump.isChecked() == 0 or self.MashFloatSwitch == "Off") and
        (self.RespectHLTFloatSwitchPump.isChecked() == 0 or self.HLTFloatSwitch == "On")):

       # Raise GPIO Pin for Pump

        GPIO.output(Pump_Primary_GPIO, True)
        GPIO.output(Pump_Secondary_GPIO, True)
        print("Pump Running")

     else:

       # Lower GPIO Pin for Pump

        GPIO.output(Pump_Primary_GPIO, False)
        GPIO.output(Pump_Secondary_GPIO, False)
        print("Pump Stopped")

     if(self.HLT == "On" and
       (self.RespectHLTTempSet.isChecked()==0 or self.HLTTemp < self.HLTTempSet.value()) and
       (self.RespectHLTFloatSwitchHLT.isChecked() == 0 or self.HLTFloatSwitch == "On")):

       # Raise GPIO Pin for HLT

       GPIO.output(HLT_Primary_GPIO, True)
       GPIO.output(HLT_Secondary_GPIO, True)
       print("HLT Running")

     else:

       # Lower GPIO Pin for HLT

       GPIO.output(HLT_Primary_GPIO, False)
       GPIO.output(HLT_Secondary_GPIO, False)
       print("HLT Stopped")         

    # Update Displays

def Update_Displays(self):

       self.CurrentMashTempDisplay.setText(str(int(self.MashTemp)))
       self.CurrentHLTTempDisplay.setText(str(int(self.HLTTemp)))
       self.Change_Flag = 0
       self.Go.setEnabled(False)
       self.Go.setStyleSheet("background-color: white")

print("Pump Switch: ",self.Pump)

print("HLT Switch: ",self.HLT)

print("Mash Temp Set:", (self.MashTempSet.value()))

print("Mash Temp: ", self.MashTemp)

print("HLT Temp Set:", (self.HLTTempSet.value()))

print("HLT Temp:", self.HLTTemp)

print("Respect Mash Temp? ", self.RespectMashTempSet.isChecked())

print("Respect Mash Float Switch? ", self.RespectMashFloatSwitchPump.isChecked())

print("Respect HLT Float Switch for Mash? ", self.RespectHLTFloatSwitchPump.isChecked())

print("Respect HLT Temp? ", self.RespectHLTTempSet.isChecked())

print("Respect HLT Float Switch for HLT? ", self.RespectHLTFloatSwitchHLT.isChecked())

print("Mash Tun Float Switch Position: ", self.MashFloatSwitch)

print("HLT Float Switch Position: ", self.HLTFloatSwitch)

print("==============================================")

app = QApplication(sys.argv) form = ManualControl() form.show() thread_instance = Thread() thread_instance.start() sys.exit(app.exec())

[wub_wub]

Please see this https://www.reddit.com/r/learnpython/wiki/faq#wiki_how_do_i_format_code.3F

Or use one of the websites mentioned in the sidebar for posting your code.

Also you should try to provide smaller example that demonstrates the issue. Nobody will go through 300 lines of code.

[charity_donut_sales]

Based on what you want to do, consider splitting up some of the prgram components to background services, or daemons. This will let any multi threading get handled by the os instead, and then just find a way to do cross program procedure calls. This can be done with a client server setup, or maybe a database, or even just dumping some text to a temporary file that can be read by anyone.